Paper take-up mechanism for movable platen



Dec. 15, 1964 D. J. SMITHBAUER 3,161,277

PAPER TAKE-UP MECHANISM FOR MOVABLE PLATEN Fil ed Oct. 22, 1962 2 Sheets-Sheet 1 I 74 24 50 a 55.1 Z

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INVENTOR. Poly/a: 0 .ZfN/IHEHIJER. 76 BY WMMG $54 .HTIORIVEX Filed Oct. 22, 1962 PAPER TAKEI-UP MECHANISM FOR MOVABLE PLATEN 2 Sheets-Sheet 2 IN VENTOR. Emma Jfvzzuaavaz .1717 DRIVE .1.

United States Patent Ohhce 3,ll,277 Patented Dec. 15, 1964 3,161,277 PAPER TAKE-UP MECHANESM FOR MOVAPQLE PLATEN Donald J. Smithbauer, Detroit, Mich, assignor to Barroughs Corporation, Detroit, Mich, a corporation of Michigan Filed (let. 22, 1962, Ser. N 232,237 2 iairns. (Q1. l97133) This invention relates generally to printing apparatus and particularly to mechanism for taking up slack of a paper web of the printing apparatus.

One of the objects of the present invention is to provide an improved mechanism for holding a paper web taut for all positions of a retractable platen about which the paper web is looped.

Another object of the invention is to provide for a printing apparatus having a retractable platen and a feeder to feed a paper Web looped about the platen, a mechanism operable in synchronization with the retracting operation of the platen to maintain the web taut in all positions of the platen.

A further object of the invention is to provide in a printing apparatus of the above mentioned character an inexpensive, efficiently operating web slack take-up mechanism.

Other objects of the invention will become apparent from the following detailed description, taken in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary plan View of a printing apparatus embodying features of the invention;

FEG. 2 is a fragmentary side view, and

FIG. 3 is an enlarged fragmentary side view.

Referring to the drawings by characters of reference, the printing apparatus comprises in general a supporting means or frame it a roll type platen 12, one or more vertically positionable print heads 14 and the usual print hammers 1.6, only one of which is shown. The frame it) may be of any suitable construction and may include a pair of laterally positioned side frame members 13. Secured respectively to the outer sides of the frame members 18 are oppositely positioned mounting plates 29. These mounting plates 26 extend upwardly and secured in and to each of the plates, near the upper ends thereof are aligned pivot pins 22 on which are pivoted the lower ends of a pair of lever arms as. The lever arms 24 extend upwardly from their pivot pins 22 and the platen 12 is journalled, as at 26, in the upper ends of the lever arms 24, the platen being of the so-called freely rotatable type.

T he mechanism for positioning the print heads 14 and for operating the hammers 16 are not shown or described in detail as they are well-known expedients and form no part of the present invention. For a more detail description of the printing apparatus reference may be had to the pending application of Robert S. Bradshaw, SN. 838,468, filed September 8, 1959, now Patent No. 2,999,166 issued August 15, 1961, of common assignee.

Spaced laterally from the axis of the platen 12 there is a paper feeder, designated generally by the numeral 30 which is of the type particularly adapted for feeding a web 32 of so-called fan-fold paper to a platen, the feeder being intermittently operated in accordance with line spacing required at the platen 12. These feeders are commonly referred to as tractor feeders in that they include a pair of laterally positioned belts or chains which carry spaced apart pins 34 which project from the top and bottom of the casing of the device. The feed pins 34 engage in perforations 36 whichare provided in the web 32, a row of the perforations being provided along each side margin of the web. A loop of the web 32 extends around the platen 12 having a feed side 33 and a trailing side 4t For a more detail description of the web feeder 3%, reference may be had to the patents to John E. Euth, Patent No. 2,285,197, issued June 2, 1942, and John T. Davidson, Patent No. 2,919,915, issued January 5, 1960.

Mounted on each of the mounting plates 26 there is a vertically reciprocal driven member or slide 42, the slides having guide slots 44 to receive guide pins 46 which may be screw-threaded into the mounting plates 20. Near the upper ends of the slides 42 cam means is provided to operatively connect the slides respectively to the pivotal lever arms 24, the cam means including a cam slot 48 and a cam follower or pin 5i carried by each of the lever arms 24. It will be seen by reference to FIGS. 2 and 3 that the cam slots 43 are inclined such that when the slides 42 are moved downwardly the arms 24 are pivoted clockwise to move the platen 12 to its retracted position, shown in dot and dash lines in FIG. 3.

The slides are raised and lowered by a pair of timed earns 52 and 54 afixed to a cam shaft 56. Below-and parallel with the cam shaft 56 there is a rotatable shaft 58 to which is atlixed a double armed cam follower 69 and a lever On the free end of one of the cam follower arms there is a roller 64 in engagement with cam 52 and on the free end of the other cam arm there is a roller 66 in en agement with cam 54. A link 68 has one end connected to the free end of the lever 62, and intermediate its ends, the link has a yieldable connection through a spring 70 with a depending operating arm 72 of a bail type lever 74. The bail 74 is afixed to a rotatable shaft 76 and has arms '78, of which only one is shown, pivotally connected, as at 80, respectively to the oppositely disposed slides 42. The platen 12 is shown in full lines in its printing position adjacent the print heads 14 and accordingly the slides 52 are in their up positions to which they were moved by cam 54. Following the printing operation, cam 52 through lever 62, link 63 and ball 74 moves the slides to their down positions and cam 48 acting on follower pins 59 pivot the lever arms 2d clockwise, as seen in FIGS. 2 and 3, to move the platen 12 to its retracted position.

Movement of the platen 12 between its printing and retracted positions tends to produce an udesirable slack in the loop of web 32 and in accordance with the inven tion, 1 provide slack take-up member or rod 82 carried by and between the upper ends of the slide members 42 to the web taut at all times. The rod 32 is positioned rearwardly of the platen 12 and extends parallel thereto above and in engagement with the upper surface of the loop feed side $3. it will thus be seen that as the platen 12 moves between its printing and retracted positions, the rod will move between its up and down positions through a corresponding distance or in synchronized relationship with the platen so as to maintain the web 32 taut about the platen throughout the range of platen movement.

While I have shown and described my device in considerable detail, it will be understood that many variations and changes may be made therein without departing from the spirit and scope of the invention.

I claim:

1. In a printing apparatus, supporting means, a rotatable platen mcunted on said supporting means, a paper web feeder spaced laterally of the axis of said platen and operable to feed a paper web looped around said platen having a feed side and a trailing side, said platen being bodily movable from a printing position toward said feeder to a retracted position tending to effect a slackening in the web between said platen and feeder, a slide member movable transversely of the axis of said platen having a first position corresponding to the printing position of said platen and a second position correspending to the retracted position of said platen, cam

' means interconnecting said slide member and said platen,

and a single slack take-up member carried by said slide member between said platen and feeder to hold the web taut about said platen throughout the range of movement of the latter.

2. In a printing apparatus, supporting means, a'rotatable platen, a paper web feeder laterally positioned from the axis of said platen and operable to feed a web'of paper looped about said platen, means pivotally mounting said platen on said supporting means for bodily movement from a printing position toward said feeder to a retracted position tending to slacken the web, a reciprocally driven member movable transversely to the path of movement of the web and mounted on said supporting means, cam means interconnecting said driven member and said platen mounting means to effect synchronized 4 1 movement of said driven member and platen, and a single slack take-up rod carried by said driven member transversely of the path of web travel and holding the web taut throughout the range of said platen movement.

References Citedin the file of this patent UNITED STATES PATENTS Bradshaw et a1 Aug. 15, 1961 

1. IN A PRINTING APPARATUS, SUPPORTING MEANS, A ROTATABLE PLATEN MOUNTED ON SAID SUPPORTING MEANS, A PAPER WEB FEEDER SPACED LATERALLY OF THE AXIS OF SAID PLATEN AND OPERABLE TO FEED A PAPER WEB LOOPED AROUND SAID PLATEN HAVING A FEED SIDE AND A TRAILLING SIDE, SAID PLATEN BEING BODILY MOVABLE FROM A PRINTING POSITION TOWARD SAID FEEDER TO A RETRACTED POSITION TENDING TO EFFECT A SLACKENING IN THE WEB BETWEEN SAID PLATEN AND FEEDER, A SLIDE MEMBER MOVABLE TRANSVERSELY OF THE AXIS OF SAID PLATEN HAVING A FIRST POSITION CORRESPONDING TO THE PRINTING POSITION OF SAID PLATEN AND A SECOND POSITION CORRESPONDING TO THE RETRACTED POSITION OF SAID PLATEN, CAM MEANS INTERCONNECTION SAID SLIDE MEMBER AND SAID PLATEN, 